Overview:

The use of alcohol and other psychoactive substances has been recorded throughout history, often with the primary aim of changing an individual’s mood or relieving the distress of harsh circumstances.

Early examples include the chewing of tobacco leaves or coca (cocaine) in North America and Peru, respectively. Humans are clearly vulnerable to the desire to use substances; this is illustrated by the fact that alcohol and other psychoactive substances remain a leading cause of medical and social problems worldwide and cause psychoactive substance use disorders.

World Health Organization (WHO) statistics report that alcohol is the primary causative factor in 4 percent of the global burden of disease. [1]

Drug:

A drug is deﬁned (by WHO) as any substance that, when taken into the living organism, may modify one or more of its functions. This deﬁnition conceptualises ‘drug’ in a very broad way, including not only the medic at ions but also the other pharmacologically active substances.

The words ‘drug addiction’ and ‘drug addict’ were dropped from scientiﬁc use due to their derogatory connotation. Instead ‘ drug abuse’, ‘ drug dependence’, ‘ harmful use’, ‘misuse’, and ‘psychoactive substance use disorders’ are the terms used in the current nomenclature.

A psychoactive drug is one that is capable of altering the mental functioning.

There are four important patterns of substance use disorders, which may overlap with each other:

1. Acute intoxication

2. Withdrawal state

3. Dependence syndrome

4. Harmful use.

The other syndromes associated with the psychoactive substance use in ICD-10 include psychotic disorder, amnesic syndrome, and residual and late-onset (delayed onset) psychotic disorder.

Acute Intoxication:

According to ICD-10, acute intoxication is a transient condition following the administration of alcohol or other psycho active substance, resulting in disturbances in level of consciousness, cognition, perception, affect or behaviour, or other psychophysiological functions and responses. This is usually associated with high blood levels of the drug. [2]

The disturbances are directly related to the acute pharmacological effects of the substance and resolve with time, with complete recovery, except where tissue damage or other complications have arisen. [3]

However, in certain cases where the threshold is low (due to a serious medical illness such as chronic renal failure or idiosyncratic sensitivity) even a low dose may lead to intoxication. The intensity of intoxication lessens with time, and effects eventually disappear in the absence of further use of the substance. The recovery is therefore complete, except where tissue damage or another complication has arisen.

The following codes may be used to indicate whether the acute intoxication was associated with any complications:

Uncomplicated (symptoms of varying severity, usually dose-dependent, particularly at high dose levels);

With trauma or other bodily injury;

With other medical complications (such as haematemesis, inhalation of vomitus);

With delirium;

With perceptual distortions;

With coma;

With convulsions;

Pathological intoxication (only for alcohol). [2]

The nature of these complications depends on the pharmacological class of substance and mode of administration. [3]

Withdrawal State:

A withdrawal state is characterised by a group of symptoms of variable clustering and severity occurring on absolute or relative withdrawal of a psychoactive substance after persistent use of that substance. The onset and course of the withdrawal state are time-limited and are related to the type of psychoactive substance and dose being used immediately before cessation or reduction of use. [3]

The withdrawal state may be complicated by convulsions. Typically, the patient reports that the withdrawal symptoms are relieved by further substance use.

Dependence Syndrome:

A cluster of behavioural, cognitive, and physiological phenomena that develop after repeated substance use and that typically include a strong desire to take the drug, difficulties in controlling its use, persisting in its use despite harmful consequences, a higher priority given to drug use than to other activities and obligations, increased tolerance, and sometimes a physical withdrawal state.

The dependence syndrome may be present for a specific psychoactive substance (e.g. tobacco, alcohol, or diazepam), for a class of substances (e.g. opioid drugs), or for a wider range of pharmacologically different psychoactive substances. [3]

A central descriptive characteristic of the dependence syndrome is the desire (often strong and sometimes overpowering) to take psycho active substances (which may or may not have been medically prescribed), alcohol, or tobacco. There may be evidence that return to substance use after a period of abstinence leads to a more rapid reappearance of other features of the syndrome than occurs with non dependent individuals.

A deﬁnite diagnosis of dependence should usually be made only if at least three of the following have been experienced or exhibited at sometime during the previous year:

A strong desire or sense of compulsion to take the substance.

Difﬁculties in controlling the substance-taking behaviour in terms of its onset, termination, or levels of use.

A physiological withdrawal state when the substance use has ceased or reduced, as evidenced by the characteristic withdrawal syndrome for the substance; or use of the same (or a closely related) substance with the intention of relieving or avoiding withdrawal symptoms.

Evidence of tolerance, such that increased doses of the psychoactive substance are required in order to achieve effects originally produced by lower doses (clear examples of this are found in the alcohol and opiate dependent individuals who may take daily doses that are sufﬁcient to incapacitate or kill non-tolerant users).

Progressive neglect of alternative pleasures or interests because of psychoactive substance use, increased amount of time necessary to obtain or take the substance or to recover from its effects.

Persisting with substance use despite clear evidence of overtly harmful consequences, such as harm to the liver through excessive drinking, depressive mood states consequent to periods of heavy substance use, or drug-related impairment of cognitive functioning; efforts should be made to determine that the user was actually, or could be expected to be, aware of the nature and extent of the harm.

A narrowing of personal repertoire of patterns of psychoactive substance use has also described as a characteristic feature of the dependence syndrome (e.g. a tendency to drink in the same way on weekdays and weekends, regardless of the social constraints that determine appropriate drinking behaviour).

The dependence syndrome can be further coded as (ICD-10):

currently abstinent

The currently abstinent, but in a protected environment (e.g. in hospital, in a therapeutic community, in prison, etc.)

currently on a clinically supervised maintenance or replacement regime (controlled dependence, e.g. with methadone; nicotine gum or nicotine patch)

currently abstinent, but receiving treatment with aversive or blocking drugs (e.g. naltrexone or disulﬁram); v. currently using the substance (active dependence)

Harmful Use:

Harmful use is characterise by:

Continued drug use, despite the awareness of harmful medical and/or social effect of the drug being use, and/or [2]

A pattern of psychoactive substance use that is causing damage to health. The damage may physical (as in cases of hepatitis from the self-administration of inject psychoactive substances) or mental (e.g. episodes of depressive disorder secondary to heavy consumption of alcohol). [3]

Harmful use is not diagnose, if a dependence syndrome is present. DSM-IV-TR uses the term substance abuse instead, with minor variations in description. [2]

Why do people use substances ?

There are a myriad of reasons why someone might take a substance at a given time; however, some general reasons apply and are listed below.

The initial reason for taking a substance is often straightforward, but may become more complex and change over time.

Pleasurable experiences:

About one-fifth of drug use is primarily to gain pleasure, usually in the form of a buzz or high, numbness, drowsiness, or comfort. Those who experience energy and confidence will often use to try and relive the initial experience they encountered.

Availability:

The availability of most psychoactive substances is limit in one way or another. If a substance is easily available people are more likely to use it; however, illegal substances also hold a particular fascination to some individuals. Psychoactive substances are usually obtained in one of three ways:

Purchased illegally: this category includes most of the other substances nicotine, alcohol, and solvents under certain age limits. Control of the availability of such drugs depends on political action and requires extensive activity by the police and other enforcement agencies to detect and control the importation and distribution of drugs.

Anxiety disorders:

They are the commonest form of psychiatric disorder and many people take drugs (especially alcohol and benzodiazepines) to reduce anxiety. Those with undiagnose social anxiety disorder are the most likely to do so.

Self-medication:

It is for psychiatric co-morbidities is extremely common, with the aim of reducing unwant symptoms. Alcohol is use in anxiety, depression, and stress-related disorders. Stimulants and cannabis are commonly taken by schizophrenics and those with bipolar disorder.

Relieving physical symptoms:

Such as pain is a relatively common reason for substance use. People with chronic pain syndromes or neurological conditions such as multiple sclerosis are the frequent users.

Boredom:

It is occasionally cite as a reason to take drugs, especially amongest young men in difficult social circumstances.

Peer pressure:

It may be prevalent amongst teenagers and university students. Personal vulnerability (a lack of personal resources needed to cope with the challenges of life) is a cause of the success of peer pressure.

Attitudes of the community:

Some social, cultural, and religious groups disapprove of drug taking, and this shared value helps to restrain its members. In other groups, drug taking is condoned or even encouraged and it gives a person status among his peers.

Dependence and tolerance:

It develop as time progresses, and a physical and psychological ‘need’ for the drug will take over from previous reasons for use. [1]

Terminology related to the use of psychoactive substances:

The terms use are common to the DSM-IV and ICD-10 classifications, and are internationally agree.

Intoxication:

It is the direct psychological and physical effects of the substance that are dose dependent and time limited. They are individual to the substance and typically include both pleasurable and unpleasant symptoms. [1]

Harmful use:

A pattern of psychoactive substance use that is causing damage to health. The damage may be physical (for example, abscesses due to the self-administration of injected substances) or mental (e.g. memory loss secondary to heavy consumption of alcohol). [1]

Dependence:

A syndrome that includes withdrawal states, tolerance, and other features such as persistent use despite harmful effects. Dependence may be both physical (when physiological tolerance occurs) and psychological. [1]

A cluster of behavioural, cognitive, and physiological phenomena that develop after repeated substance use and that typically include a strong desire to take the drug, difficulties in controlling its use, persisting in its use despite harmful consequences, a higher priority given to drug use than to other activities and obligations, increased tolerance, and sometimes a physical withdrawal state.

The dependence syndrome may present for a specific psychoactive substance (e.g. tobacco, alcohol, or diazepam), for a class of substances (e.g. opioid drugs), or for a wider range of pharmacologically different psychoactive substances. [3]

Tolerance:

It is the state in which repeat administration leads to decreasing effect. [1]

Withdrawal:

It is a set of symptoms and signs occurring when a substance is reduce or stop after persistent usage. The nature, time to onset, and course of the symptoms vary for different substances and may include convulsions or delirium. [1]

Substance-induced psychosis:

A cluster of psychotic phenomena that occur during or following psychoactive substance use but that are not explain on the basis of acute intoxication alone and do not form part of a withdrawal state. The disorder is characterize by hallucinations (typically auditory, but often in more than one sensory modality), perceptual distortions, delusions (often of a paranoid or persecutory nature), psychomotor disturbances (excitement or stupor), and an abnormal affect, which may range from intense fear to ecstasy. The sensorium is usually clear but some degree of clouding of consciousness, though not severe confusion, may be present. [3]

Amnesic syndrome:

It is the chronic prominent impairment of recent and remote memory. Immediate recall is usually preserve and recent memory is characteristically more disturb than remote memory. Disturbances of time sense and ordering of events are usually evident, as are difficulties in learning new material. Confabulation may mark but is not invariably present. Other cognitive functions are usually relatively well preserve and amnesic defects are out of proportion to other disturbances.

It may cause by intoxication or chronic use of alcohol, solvents, benzodiazepines, and possibly cannabis. [1]